Now to the dramatic capture of the suspected mastermind of the attack on the U.S. Consulate in benghazi. That left four Americans dead. American commandos grabbed him in a raid inside Libya and he's now being brought here to face charges. ABC news chief investigative correspondent Brian Ross is here. Reporter: The accused mastermind of those benghazi attacks is being interrogated on a U.S. Navy ship in the M mediterrane mediterranean. After being captured in a lightning-quick nighttime raid by special forces right under the noses of the Libyan government and the suspect's own militant fighters. Abu khatallah had been sought by the U.S. For 21 months when he was finally captured in benghazi by U.S. Special forces. No matter how long it takes, we will find those responsible and we will bring them to justice. Reporter: The capture came as welcome news to the families of the four Americans killed in the massive attack on U.S. Facilities in benghazi. But the mother of one of them, Sean smith told our San Diego affiliate KGTV she still has many questions about what happened. I'm glad they got one of them. There was a whole bunch that set fire to that place. Reporter: U.s. Officials hope Abu khatallah can provide information on the others supposedly involved in the attack seen in these images released by the FBI. They are still at large. He is really the go-to guy when it comes to intelligence about the other conspirators involved with the attack on benghazi. Reporter: Benghazi has fueled a bitter and partisan debate that has focused on the role of then secretary of state Hillary Clinton. She was asked some tough questions about it on Fox News last night. I had a very clear sense of priorities. Protect our people, get them to safety. Reporter: U.s. Officials tell ABC news that khatallah had been under surveillance in Libya for months, in fact, interviewed by reporters for CNN and others denying his involvement and flaunting his presence in benghazi. If a CNN reporter can have an interview witim openly in a cafe, why couldn't we get to him sooner? Reporter: So the key questions for Abu khatallah are who ordered this and why? Answers that if truthful could help resolve that dispute in this country just over how it happened and who ordered it on September 11th. Still so many unanswered questions. What's next? Where will he face trial? In Washington, D.C. On three charges which could include the death penalty.

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